Lancer Systems builds the L5AWM Blackout magazine (part no. 999-000-4280-05) specifically for AR-15 rifles chambered in .300 AAC Blackout, engineered around heavy subsonic loads, particularly 200-grain-plus projectiles that don’t stack properly in a standard .223/5.56 magazine. The updated internal geometry increases feeding reliability with these longer, heavier bullets, and the opaque black polymer body ships with a contrasting Flat Dark Earth floor plate for quick visual identification of the caliber in a mag pouch. Holding 20 rounds at 6.55 inches overall, it’s purpose-built rather than adapted from a 5.56 design. For Lancer Systems owners running a suppressed or subsonic .300 Blackout build, this AR-15 magazine is a purpose-engineered fit.

Key Specifications

• Chambered in .300 AAC Blackout.
• Holds 20 rounds.
• Fits the AR-15 platform.
• Engineered for heavy subsonic loads, especially 200+ grain projectiles.
• Features updated internal geometry for reliable feeding of longer, heavier bullets.
• Molded in opaque black polymer.
• Ships with a contrasting Flat Dark Earth floor plate for visual caliber ID.
• Measures 6.55 inches in overall length.

Frequently Asked Questions

Why does this magazine matter for subsonic .300 Blackout? Heavy subsonic bullets, especially 200+ grain projectiles, don’t stack properly in a standard 5.56-pattern magazine; the L5AWM’s geometry is built to feed them reliably.

How can I tell this magazine apart from a 5.56 mag at a glance? It ships with a contrasting Flat Dark Earth floor plate against the black body for quick caliber identification.

Buy the Lancer L5AWM .300 Blackout Magazine

Purpose-engineered for heavy subsonic .300 Blackout loads, this Lancer L5AWM magazine feeds reliably where a standard 5.56 mag falls short. Order it from our Lubbock, Texas gun shop for fast, insured shipping.